<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script type="text/javascript" src="jquery-v2.2.1.min.js"></script>
</head>
<body>

</body>
<script>
    $('body').ready(function () {
        console.log("===========");
    });

    $('body').on('ready', function () {
        console.log("123");
    });
</script>
</html>